Our research

We try to understand the “rules of the game” that explain how cells
function and evolve. We study budding yeast, using experimental
evolution, genetic analysis, synthetic biology, and cell biology. We
try to make quantitative measurements that discriminate amongst
different classes of models. Members of the lab come from both
biology and physics backgrounds.

How does biological novelty evolve? Because we lack time travel,
this process is difficult to study in nature, and we therefore apply
selective pressure in the laboratory. We have evolved
multicellularity, altered mating preferences, circadian oscillators,
genetic instability, and new connections between signaling pathways
and have developed methods to find the mutations that cause these
new phenotypes. We are interested both in general questions about
what determines evolutionary trajectories and the specific
mechanisms that organisms invent to produce novel traits.

How do cells accomplish specific tasks and how did these solutions
evolve? We follow the Feynman principle of “What I cannot create, I
cannot understand” by engineering and analyzing the behavior of new
yeast strains. As examples, we have used synthetic biology to
support the notions that the efficient use of secreted public goods
drove the evolution of multicellularity, that multicellularity arose
before cellular differentiation, and that novel symbioses could
arise without requiring previous evolutionary co-adaptation.

How do cells respond and adapt to their environment to maximize the
chance that they survive and reproduce? Achieving these aims
requires the coordination of thousands of reactions under a wide
range of inter- and extracellular conditions. We are exploring how
yeast cells respond to sudden starvation and have discovered that
they can rapidly halt their cell cycles, at any stage, and then,
later, slowly resume cell division. We are asking how they arrest,
whether the arrest destabilizes the genome, and how cells adapt to
start dividing again.

Finally, we collaborate with David Nelson (Physics and MCB) to
combine theory and experiment to investigate population dynamics and
evolution in space and time.